Automatically translated from Basque, translation may contain errors. More information here. Elhuyarren itzultzaile automatikoaren logoa

Ingeotyc geology recommends not to extend the Yesa reservoir

  • It concludes that the right side of the reservoir remains unstable and therefore there is a level of risk. The report was prepared by geologists Valentín Ibarra and Tomás Morales of the company Ingeotyc on behalf of the City Council of Sangüesa.
Argazkia: AraInfo

The work is actually a reading of what was published by the Spanish Ministry of Ecological Transition in 2021. This work was carried out by the College of Engineers of Ports, Canals and Roads, but given its complexity the City Hall of Sangüesa requested a report to Ingeotyci, now published.

The final recommendation in the report is very clear. He says that even today there are displacements on the right side, that the observations currently made are limited and that uncertainty about the slope dynamics is significant, which does not guarantee the necessary security in situations that can be caused by earthquakes or other events. Consequently, it is not appropriate to change the water level in this area and it is therefore recommended that the Yesa reservoir should not be kept to the level required by the extension.

Problems since 1928

The report begins with a historical review of the reservoir and recalls that since the beginning of its construction in 1928 it has given problems to the slopes on the right. In fact, immediately after its beginning, the works were paralyzed due to the great movements suffered. Then came the Civil War and eventually the reservoir began to work in 1959.

Between 2003 and 2011, for example, the fin had a movement of 15 millimeters. In 2006, there was also another big movement on the hillside, it was concealed, but the press did. Also in 2013, as a result of the heavy flooding, two landslides changed the landscape and had to evict the urbanizations Tranquility and Observatory of Yesa. In 2014, the Spanish government expropriated the land of the urbanizations and nobody lives there anymore.

Instability is inherent in its compliance and emptying

According to the report, when the work of expansion of the reservoir began, the capacity of the right slope to withstand the works and their permeability was analyzed, but it was not considered to study its geomorphological evolution. Due attention has also not been paid to the movements of the nails holding the dam: “Current measurements have significant deficiencies and automatic auscultation tools must be put in place that provide continuous records.”

Although geologists acknowledge that important works have been carried out on the hillside, they consider that the hillside is still unstable, it must be taken into account that the filling and emptying processes of the reservoir are intrinsically responsible for instability and retest the hillside even without seismic movements.

The reservoir currently has a capacity of 446 cubic hectometers, an increase of 1,525 hectares. Work on extending the reservoir began in 2003 with a budget of EUR 113 million and has already exceeded EUR 500 million. This station is one of the most water collected by Esa, but this week it has only 219 cubic hectometers, which accounts for 48% of its capacity. In addition to the risks of the hillside, many experts believe that it is not worth expanding the reservoir because, among other things, the scarcity of rainfall will make it difficult to comply with it.

You are interested in the channel: Esa urtegia
Closure of the extension of the Esa reservoir
According to the Rio Aragon Association, the expansion of the Esa reservoir is paralyzed by "insecurity". This group requests the suspension of the contract and the revision of the project. They call on the Ebro Hydrographic Confederation to accept "unfeasibility".

They want to end the expansion of the Esa reservoir by 2027
The works began 22 years ago, but the construction of the reservoir has had many problems, and the works are still going on. In response to the request of Río Aragón, the Confederación Hidrográfica del Ebro, CHE, replies that the work is scheduled for completion in 2027.

Satellite warn of the instability of the Yesa reservoir
Geological studies have warned on more than one occasion and now the warning comes from satellite surveillance: The Yesa reservoir is not stable. Copernicus, the European Union’s Earth observation programme, has detected a ‘movement’ on the slopes of the reservoir.

D. Alfredo Ollero Ojeda
“Rivers are sinking deeper and deeper into their channels”
The Ebro is the largest river in the Basque Country. We have spoken on its shore, at the entrance to Zaragoza, where Ollero lives, accompanied by the slow lertxuna, the crazy song of birds and the gentle flow of the river, the afternoon that has erupted spring at 33 degrees,... [+]

Remírez states that the Government of Spain acts rigorously in the Yesa dam, 22 years after the beginning of the works
The Vice-President of the Government of Navarre, Javier Remirez, explained in the Parliament of Navarre a study on the safety of urgency which was completed fifteen months ago and which has not been published so far. The investigation was carried out on behalf of the Government... [+]

Eguneraketa berriak daude